PROJECT SUMMARY/ABSTRACT Cardiovascular disease (CVD) is the leading cause of mortality in the US and for Asian Americans and Pacific Islander (AAPIs) adults age 65 and older. The prevalence of CVD has been well documented for non-Hispanic white, African American, and Hispanic populations. However, CVD morbidity and mortality disproportionately impacts AAPIs living in the US and the true magnitude of CVD by specific racial subgroup (e.g. Asian Indian, Chinese, Filipino, Japanese, Korean, Vietnamese, and Native Hawaiian and Pacific Islander) has not been accurately characterized. The paucity of data on AAPI subgroups has resulted in the inability to precisely estimate CVD incidence and prevalence and develop appropriate clinical guidelines and recommendations for CVD research priorities. Moreover, traditional CVD risk factors (e.g. hypertension, body mass index, and diabetes) are unequally distributed across AAPI subgroups and the relative importance of these CVD risk factors is unclear. Neighborhood context (e.g. median household income, neighborhood deprivation, and rural/urban status) has been identified as an important determinant of health status and underlying factor in health disparities. However, the relationship between neighborhood context and CVD health in AAPI subgroups is not well understood. AAPIs represent more than 40 cultures of origin and 100 different languages and are projected to be the fastest growing racial group in the US by 2050. AAPI older adults will also be the fastest growing group in the US elderly population. Most AAPI older adults are foreign-born and recent immigrants to the US, and typically have low education levels, limited English proficiencies, and high poverty rates. AAPI older adults are a particularly vulnerable population as they face the compounding effects of minority group status and older age. Furthermore, these current issues are exacerbated by the absence of AAPIs in research. The primary objectives of this study are to identify the prevalence and determinants of CVD in AAPI subgroups and determine the associations between neighborhood context and individual health status in AAPI older adults through secondary data analysis of US Census Bureau data and the Medicare Health Outcomes Survey (HOS). We propose multilevel regression analysis of the HOS (N=1,017500), a nationally representative survey administered by the Centers for Medicare & Medicaid Services. The HOS is a unique dataset that began collecting expanded ethnic and racial data in 2011, including 4 Hispanic-origin and 11 AAPI-origin categories, which allows for disaggregated analysis of AAPI subgroups (44,705 self-reported an AAPI subgroup). The HOS will be linked to geographic-level census data to investigate neighborhood factors that impact individual differences in health status. We expect that the findings will establish a better understanding of the CVD prevalence in AAPI subgroups and the intersections between neighborhood and CVD and race/ethnicity. The proposed research will inform culturally relevant strategies to improve CVD health in high-risk groups, manage CVD risk factors, and reduce CVD morbidity and mortality in diverse older adults.